JP5618766B2 - Radical measuring device and radical measuring tube - Google Patents

Description

  The present invention relates to a radical measurement device and a radical measurement tube for measuring the heat of bonding of radicals.

  Processes using radicals (chemical species having unpaired electrons) as reactive species, such as ashing and chemical etching, are known. The radical is generated by converting the raw material gas into plasma. In general, radicals are unstable compared to molecules, and some of the generated radicals are combined (recombined) with each other or with other chemical species to become molecules or the like, and the activity disappears (deactivates). . Deactivation occurs mainly at a solid phase surface such as a process chamber, and its speed depends on the material constituting the surface. For this reason, the surface which a radical contacts is comprised with the material with the small speed | velocity | rate (recombination coefficient) of the radical deactivation, the radical amount lost by deactivation is reduced, and the speed of the desired reaction is improved. It becomes possible.

  The recombination coefficient for various materials of a specific radical species can be determined by measurement. For example, Non-Patent Document 1 discloses a measuring device that obtains the recombination coefficient of hydrogen radicals of various materials from the rate of radical concentration reduction due to deactivation. The measurement apparatus includes a radical generation chamber that generates radicals of the source gas and a measurement tube that communicates with the radical generation chamber. A sample tube made of a sample material is disposed in the measurement tube, and a thermocouple movable along the axial direction of the sample tube is provided. The radicals of the source gas produced in the radical production chamber flow into the measuring tube by the vacuum exhaust means and are deactivated on the surface of the sample, so that the concentration thereof gradually decreases. A radical concentration gradient is obtained from the temperature measured by the thermocouple (radical bond heat), and the recombination coefficient of the radical with respect to the sample material is calculated from the concentration gradient.

R.K.Grubbs, S.M.George "Attenuation of hydrogen radicals traveling under flowing gas conditions through tubes of different materials" The Journal of Vacuum Science and Technology A Vol. 24 No. 3 P486 American Vacuum Society

  However, in the measuring device described in Patent Document 1, a sample tube formed in a circular tube shape is used. This is because the transport rate of radicals from the sample surface to the thermocouple is made uniform, and the recombination coefficient calculation formula is simplified. However, in many cases, it is difficult to process a sample material supplied in a flat plate shape into a circular tube shape, resulting in high cost. Even when the sample material is adhered to the substrate by surface treatment or the like, the surface treatment is difficult in the circular tube shape. On the other hand, if a sample tube can be created by combining flat sample materials, the sample tube can be easily prepared.

  In view of the circumstances as described above, an object of the present invention is to provide a radical measuring device and a radical measuring tube having a sample tube formed by a combination of flat sample materials.

In order to achieve the above object, a radical measurement apparatus according to an embodiment of the present invention includes a radical generation chamber, a measurement tube, a support, and a vacuum exhaust unit.
The radical generation chamber has radical generation means for generating radicals of the source gas by generating plasma of the source gas.
The measurement tube communicates with the radical generation chamber.
The said support body is arrange | positioned in the said measurement tube, and supports each said sample plate so that a tubular sample tube may be formed with the sample plate which consists of a several flat plate-shaped sample material.
The evacuation unit evacuates the measurement tube.
The temperature sensor is inserted into the sample tube and is movable along the axial direction of the sample tube.

In order to achieve the above object, a radical measurement tube according to an embodiment of the present invention includes a measurement tube and a support.
The measuring tube forms a radical flow path.
The said support body is arrange | positioned in the said measurement tube, and supports each said sample plate so that a tubular sample tube may be formed with the sample plate which consists of a several flat sample material.

It is a mimetic diagram showing a radical measuring device concerning an embodiment of the present invention. It is a perspective view which shows the measuring tube of the state in which the supporting member of the same radical measuring apparatus is not installed. It is a perspective view which shows the supporting member of the radical measuring apparatus. It is a perspective view which shows the combined support member of the same radical measuring apparatus. It is a perspective view which shows the measuring tube in which the supporting member of the radical measuring device was inserted. It is a top view which shows the measuring tube in which the supporting member of the radical measuring device was inserted. It is a perspective view which shows the sample plate arrange | positioned at the same radical measuring apparatus. It is a perspective view which shows the measuring tube in which the sample plate of the radical measuring apparatus was installed. It is a top view which shows the measuring tube in which the sample plate of the radical measuring apparatus was installed. It is a perspective view which shows the measuring tube in which the shielding cover of the radical measuring device was installed. It is a top view which shows the measuring tube in which the shielding cover of the radical measuring apparatus was installed. It is a table | surface which shows the result of the temperature measurement of the radical measuring apparatus which concerns on an Example and a comparative example.

A radical measurement device according to an embodiment of the present invention includes a radical generation chamber, a measurement tube, a support, and a vacuum exhaust unit.
The radical generation chamber has radical generation means for generating radicals of the source gas by generating plasma of the source gas.
The measurement tube communicates with the radical generation chamber.
The said support body is arrange | positioned in the said measurement tube, and supports each said sample plate so that a tubular sample tube may be formed with the sample plate which consists of a several flat plate-shaped sample material.
The evacuation unit evacuates the measurement tube.
The temperature sensor is inserted into the sample tube and is movable along the axial direction of the sample tube.

  The radical generated in the radical generation chamber flows from the radical generation chamber toward the measuring tube due to a pressure difference caused by the vacuum exhaust section. Of the radicals that flow into the measuring tube, those that reach the surface of the sample tube are deactivated on the surface, so that the radical concentration gradually decreases. By measuring the heat of recombination of radicals on the surface of the temperature sensor with the temperature sensor, the amount of decrease in radical concentration can be calculated at a plurality of positions in the measuring tube. From the amount of decrease in the radical concentration, it is possible to calculate a recombination coefficient indicating the degree (rate) of deactivation of the radical species with respect to the sample material. Here, according to the said structure, a sample tube is formed in the inside of a measurement tube, when a flat sample plate is supported by a support body. A flat sample plate is easier to mold than those having a shape such as a curved plate, and surface treatment is also easy.

  The support may be in surface contact with the measurement tube and the plurality of sample plates.

  When the support is in surface contact with the measurement tube and the sample plate, the thermal conductivity between the sample plate and the measurement tube can be improved. In this radical measurement device, the temperature of the outer wall of the measurement tube is handled as the temperature of the sample plate, so that the smaller the temperature difference between the sample plate and the measurement tube, the more accurate measurement of radical binding heat is possible.

  The radical measurement device may further include a covering member that is disposed in the measurement tube and covers the support and the end surfaces of the sample plate so as not to be exposed in the measurement tube.

  In order to measure the deactivation of radicals flowing into the measurement tube on the sample surface as described above, it is desirable that no surface other than the sample surface is exposed in the measurement tube. According to the said structure, the support body and the end surface of a sample board are coat | covered with a coating | coated member, and it is possible to prevent the deactivation of the radical in the said surface.

  The support may include a plurality of support members having a first surface in surface contact with the measurement tube and a second surface in surface contact with the sample plate.

  According to this configuration, since one support member supports one sample plate, the first surface can be planar. For this reason, generation | occurrence | production of the clearance gap between a supporting member and a sample board can be prevented, and the heat conduction between a supporting member and a sample board can be made favorable.

  The measurement tube may be a circular tube, and the support may support the sample plate such that the sample tube is a rectangular tube.

  A circular tube has a higher pressure resistance than tubes of other shapes, and can be made with less material if the pressure resistance is the same. For this reason, the measuring tube is a circular tube, and a rectangular tube in which a flat sample plate is combined is arranged.

In order to achieve the above object, a radical measurement tube according to an embodiment of the present invention includes a measurement tube and a support.
The measuring tube forms a radical flow path.
The said support body is arrange | positioned in the said measurement tube, and supports each said sample plate so that a tubular sample tube may be formed with the sample plate which consists of a several flat sample material.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overall configuration of radical measuring device]
FIG. 1 is a schematic diagram showing a radical measuring apparatus 1 according to an embodiment of the present invention.
As shown in FIG. 1, the radical measurement device 1 includes a radical generation chamber 2, an L-shaped tube 3, a measurement tube 4, and an exhaust tube 5. An L-shaped tube 3 is connected to the radical generating chamber 2, a measuring tube 4 is connected to the L-shaped tube 3, and an exhaust tube 5 is connected to the measuring tube 4. A temperature sensor 9 is inserted into the measurement tube 4.

  The radical generation chamber 2 is a chamber in which the source gas is turned into plasma and radicals are generated. The radical generation chamber 2 is configured such that the room is isolated from the outside and the pressure difference between the room and the outside can be maintained. The radical generation chamber 2 is provided with an opening 2a through which the generated radical flows out. A plasma generator 6 and a gas introduction system 7 are connected to the radical generation chamber 2.

  The plasma generator 6 irradiates the raw material gas introduced into the radical generation chamber 2 by the gas introduction system 7 with an electromagnetic wave such as a microwave (eg, frequency: 2.45 GHz), thereby converting the raw material gas into plasma. It is configured to be possible. Further, the plasma generator 6 can also convert the source gas into plasma by excitation with a laser or the like.

  The gas introduction system 7 supplies a raw material gas into the radical generation chamber 2. The gas introduction system 7 is constituted by, for example, a gas cylinder and piping. The gas introduction system 7 can adjust the flow rate of the source gas supplied to the radical generation chamber 2.

  The L-shaped tube 3 is a tube having an L-shaped channel, and is connected to the opening 2 a of the radical generation chamber 2. The L-shaped tube 3 can be made of a material that does not cause radical deactivation described later, for example, quartz. The L-shaped tube 3 is arranged to prevent the radiant heat radiated from the plasma of the raw material gas generated in the radical generation chamber 2 from reaching the measuring tube 4. The L-shaped tube 3 has a flange 3 a connected to the radical generation chamber 2 and a flange 3 b connected to the measurement tube 4.

  The measurement tube 4 is a tube in which a sample is arranged, and is connected to the L-shaped tube 3. The measuring tube 4 is formed in a circular tube shape. The measurement tube 4 is provided with a support member 16 that supports the sample plate S and a shielding lid 18 that covers the end surfaces of the sample plate S and the support member 16. Details of these configurations will be described later. The measurement pipe 4 has a flange 4 a connected to the L-shaped pipe 3 and a flange 4 b connected to the exhaust pipe 5.

  The exhaust pipe 5 is a pipe for allowing radicals to flow through the measurement pipe 4, and is connected to the measurement pipe 4. The exhaust pipe 5 is provided with an exhaust port 5a, and an exhaust system 10 is connected to the exhaust port 5a. As will be described later, when the exhaust port 5a is close to the measurement tube 4, the gas flow in the measurement tube 4 is not a laminar flow due to the gas flow sucked into the exhaust port 5a, which affects the calculation of the combined heat. May occur. For this reason, the exhaust port 5 a and the measurement tube 4 are separated from each other by the exhaust tube 5. The opening of the exhaust pipe 5 opposite to the measurement pipe 4 is closed by a lid 12. The exhaust pipe 5 has a flange 5b connected to the measurement pipe 4 and a flange 5c to which the lid 12 is connected.

  The exhaust system 10 exhausts the gas in the space formed by the radical generation chamber 2, the L-shaped tube 3, the measurement tube 4 and the exhaust tube 5 from an exhaust port 5 a formed in the exhaust tube 5. The exhaust system 10 is constituted by, for example, a vacuum pump and piping. The exhaust system 10 can adjust the exhaust speed.

  The temperature sensor 9 detects radicals that have flowed into the measuring tube 4. The temperature sensor has a catalyst surface to which radicals adhere and recombine. The temperature sensor 9 may be, for example, an R thermocouple (+ electrode: Pt—Rh (13%) alloy, −electrode: Pt). The temperature sensor 9 is supported by a support rod 14 extending in the axial direction of the measurement tube 4 and is disposed on the central axis of the measurement tube 4.

  The support bar 14 is inserted through the exhaust pipe 5 from the measurement pipe 4, penetrates the lid 12, and extends to the outside of the exhaust pipe 5. The support bar 14 is connected to a drive mechanism 15 provided on the lid 12. The drive mechanism 15 includes a motor, gears, and the like, and drives the support rod 14 in the axial direction of the measurement tube 4. The drive mechanism 15 is configured such that the temperature sensor 9 attached to the support rod 14 can move inside the measurement tube 4. That is, the support bar 14 is driven by the drive mechanism 15, and the temperature sensor 9 attached to the support bar 14 can take an arbitrary position in the axial direction of the measurement tube 4. Note that the support rod 14 and the drive mechanism 15 are not limited to the configuration shown here, and other configurations capable of supporting and driving the temperature sensor 9 may be employed.

  The radical measuring device 1 is configured as described above. The radical generation chamber 2, the L-shaped tube 3, the measurement tube 4 and the exhaust tube 5 form a communication space (hereinafter referred to as measurement space). The measurement space is configured such that the pressure can be adjusted by the gas introduction system 7 and the exhaust system 10.

[Configuration of measuring tube]
Hereinafter, a detailed configuration of the measurement tube 4 will be described.
FIG. 2 is a perspective view showing the measurement tube 4 in a state where the support member 16 is not installed. As shown in the figure, the measuring tube 4 is a circular tube having a circular conduit. The measurement tube 4 is formed with a recess 4c for mounting the shielding lid 18 thereon. The recess 4c is lowered by one step from the contact surface of the flange 4a.

FIG. 3 is a perspective view showing the support member 16. FIG. 3A is a view of the support member 16 viewed from one direction, and FIG. 3B is a view of the support member 16 viewed from the opposite direction.
As shown in the figure, the support member 16 has a columnar shape with upper and lower surfaces of a missing circle (a part of a circle consisting of a straight line and an arc), and the first surface 16a and the second surface that contact the side surfaces. 16b. The first surface 16a is planar and is a surface on which the sample S is arranged. The second surface 16 b is a curved surface and is a surface that comes into contact with the measurement tube 4. The length of the support member 16 (the axial direction of the measurement tube 4) can be the same as the length of the measurement tube 4. The support member 16 can be made of a material having high thermal conductivity, for example, aluminum.

  The support member 16 is inserted into the measurement tube 4 in a state where the four members are combined. FIG. 4 is a perspective view showing a state in which the support member 16 is combined. As shown in the figure, the support members 16 are combined such that the first surfaces 16a are orthogonal to each other. As a result, a cylindrical shape is formed in which the inner periphery is a surface composed of four first surfaces 16a and the outer periphery is a surface composed of four second surfaces 16b.

  FIG. 5 is a perspective view showing the measurement tube 4 in which the support member 16 is inserted. FIG. 6 is a plan view showing the measurement tube 4 with the support member 16 inserted therein. As shown in these drawings, each of the four support members 16 has the second surface 6 b in surface contact with the inner peripheral surface of the measurement tube 4. Four sample plates S are placed on the measurement tube 4 in this state.

  7 is a perspective view showing a sample plate S. FIG. 7A shows one sample plate S, and FIG. 7B shows four sample plates S placed on the measuring tube 4. The sample plate S is made of a material to be measured and has a flat plate shape having substantially the same size. The sample plate S is formed in the same size as the first surface 16 a of the support member 16. Each sample plate S is placed on one support member 16 and arranged in a square tube shape as shown in FIG.

  FIG. 8 is a perspective view showing the measuring tube 4 on which the sample plate S is installed. FIG. 9 is a plan view showing the measuring tube 4 on which the sample plate S is installed. As shown in the figure, a tube made of a sample plate S (hereinafter referred to as a sample tube) is formed in the tube of the measurement tube 4. The sample plates S are in surface contact with the first surface 16a of the support member 16, respectively.

  Further, a shielding lid 18 is attached to the measurement tube 4. FIG. 10 is a perspective view showing the measurement tube 4 to which the shielding lid 18 is attached. FIG. 11 is a plan view showing the measurement tube 4 to which the shielding lid 18 is attached. In FIG. 10, the shielding lid 18 is shown separated from the measurement tube 4. As shown in these drawings, the shielding lid 18 has a disk shape having a rectangular opening. The shielding lid 18 is made of a material that does not deactivate radicals, such as quartz, and prevents the radicals from being deactivated on the end surface of the support member 16 and the end surface of the sample plate S. The size of the opening is such that the end surface of the support member 16 and the end surface of the sample plate S are covered and the maximum opening area is obtained.

  The measuring tube 4 has the above configuration. Four sample plates S are tubularly supported by the four support members 16. Thereby, it can be set as a sample tube using the flat sample board S. FIG. The flat sample plate S is easier to manufacture than a curved one, and the cost of the sample tube can be reduced. Further, the support member 16 having high thermal conductivity makes it possible to equalize the temperature of the sample tube and the temperature of the outer surface of the measurement tube 4. Furthermore, since the heat capacities of the sample plate S and the support member 16 are increased, the temperature change of the sample plate S during measurement can be reduced, and the heat of radical binding can be accurately measured.

[Radical measurement method using radical measurement device]
A measurement method using the radical measurement apparatus 1 configured as described above will be described.

  First, the measurement space is exhausted by the exhaust system 10, and the pressure is sufficiently reduced until the measurement space is cleaned. Next, the raw material gas is supplied from the gas introduction system 7 to the radical generation chamber 2. The exhaust speed of the exhaust system 10 and the supply speed of the raw material gas from the gas introduction system 7 are adjusted, and the measurement space is maintained at a predetermined pressure. In this state, in the measurement space, a gas flow of a raw material gas having a constant flow rate is formed from the radical generation chamber 2 to the exhaust port 5a via the L-shaped tube 3, the measurement tube 4, and the exhaust tube 5. Here, the gas flow flowing through the measuring tube 4 is a laminar flow.

  Next, the source gas is turned into plasma by the plasma generator 6. When electrons in the plasma collide with the molecules of the source gas, the molecular bonds are broken and radicals are generated. Since radicals are unstable and recombine and return to molecules, electron bombardment continues in plasma, so radical generation and recombination are balanced, and a predetermined concentration of radicals are present in the plasma. The generated radical flows out from the opening 2a of the radical generation chamber 2 by the gas flow, passes through the L-shaped tube 3 and flows into the measuring tube 4.

  Among the radicals flowing through the measuring tube 4, those that have reached the surface of the sample plate S are deactivated at a predetermined speed (ratio) on the surface of the sample plate S. The deactivation rate is determined by the radical species and the material of the surface of the sample plate S. Thereby, the radical concentration in the measuring tube 4 gradually decreases from upstream to downstream.

  A part of radicals flowing through the measuring tube 4 adheres to the surface of the temperature sensor 9 and recombines to generate bonding heat. The heat of binding is considered as the product of the bond dissociation energy released when the radicals are combined to form molecules and the number of radicals transported to the temperature sensor 9. Thereby, the number of radicals transported to the temperature sensor 9 from the combined heat can be obtained. If the gas flow flowing through the measuring tube 4 is a laminar flow, it is possible to calculate the concentration of radicals from the combined heat.

  The temperature sensor 9 moves in the axial direction of the measuring tube 4 after its output is measured at a specific position. The temperature sensor 9 is moved when the support bar 14 is driven by the drive mechanism 15. The output of the temperature sensor 9 is measured at the moved new position, and the movement and output measurement are repeated. By doing so, the output of the temperature sensor 9 is measured at a plurality of positions in the measuring tube 4.

  The radicals that have passed through the measurement pipe 4 flow into the exhaust pipe 5 and are exhausted from the exhaust port 5a by the exhaust system 10. Since the exhaust port 5a and the measurement tube 4 are sufficiently separated from each other, the gas flow in the measurement tube 4 is maintained as a laminar flow.

[Calculation method of recombination coefficient]
From the output of the temperature sensor 9 measured as described above, the recombination coefficient of the surface of the sample plate S of the radical species is calculated. Hereinafter, a method for calculating the recombination coefficient will be described.

The output of the temperature sensor 9, that is, the heat balance of the temperature sensor 9, can be expressed by the following equation (1).
Q1 + Q3 + Q4 = Q2 + Q5 (1)
Here, Q1 is heat lost due to radiation of electromagnetic waves from the temperature sensor 9, Q2 is heat applied to the temperature sensor 9 by radiation from plasma, and Q3 is a temperature sensor due to laminar flow of gas existing around the temperature sensor 9. Q4 is heat lost by heat conduction from the thermocouple wire of the temperature sensor 9 to the support rod 14, and Q5 is heat applied to the temperature sensor 9 by radical bonding heat generated on the surface of the temperature sensor 9. . By maintaining the position until the output of the temperature sensor 9 becomes constant, heat flows into the temperature sensor 9 (left side of the equation (1)) and heat flows out of the temperature sensor 9 (right side of the equation (1)) ) Agree with each other, and the formula (1) is established.

Q1 is Stefan-Boltzmann's law (unit area from the surface of a black body, the energy of the electromagnetic wave emitted per unit time is proportional to the fourth power of the thermodynamic temperature of the black body) ).
Q1 = σAε (Tw ⁴ −Tf ⁴ ) (2)
σ is a Stefan-Boltzmann coefficient (5.67 × 10 ⁻⁸ [W · m ⁻² · K ⁻⁴ ]), A is the surface area of the temperature sensor 9, ε is the emissivity of the temperature sensor 9, and Tw is the temperature at each measurement position. (Output of the temperature sensor 9), Tf is the gas temperature (assuming the outer wall temperature of the measuring tube 4).

Q3 can be obtained by the following equation (3).
Q3 = hA (Tw−Tf) (3)
h is the heat transfer coefficient of the temperature sensor 9 in the gas flow.

Q4 can be ignored because the cross-sectional area of the thermocouple wire of the temperature sensor 9 is sufficiently small.
Q2 can be ignored because radiation from the plasma is shielded by the L-shaped tube 3.

  As described above, Q5 which is the heat of radical binding is obtained by calculating Q1 and Q3 from the output Tw of the temperature sensor 9. The inclination of Q5 with respect to the position of the temperature sensor 9 is the attenuation coefficient α [W / m]. From this attenuation coefficient α, the recombination coefficient γ is calculated using the determinant shown in the following [Equation 1].

In the equation shown in [Formula 1], D is a radical diffusion coefficient (m ² / s), V _f is an average flow velocity (m / s) of the gas flowing through the measuring tube 8, and L is a length of one side of the sample tube ( m), v _t is the heat rate (m / t) of the radical.

  Derivation of the equation [Formula 1] will be described.

  The advection-diffusion equation of a square tube can be described as [Equation 2] below.

  Assuming a functional form as shown in [Equation 3] below and substituting it into the advection diffusion equation shown in [Equation 2], the following equation shown in [Equation 4] is obtained.

  Further, when the function form shown in [Equation 3] is substituted into the boundary condition shown in [Equation 5], the equation shown in [Equation 6] is obtained.

  The simultaneous linear equations shown in [Expression 7] are obtained from the expression shown in [Expression 4] and the expression shown in [Expression 6].

  In the equation shown in [Equation 7], in order to have a non-zero solution, γ for which the determinant shown in [Equation 8] below becomes 0 may be obtained. In the determinant shown in [Equation 8], when each coefficient is obtained, the determinant shown in [Equation 9] is obtained.

  The recombination coefficient γ can be obtained from the attenuation coefficient α using the equation [Equation 9] calculated as described above. In the present embodiment, as described above, since the heat conduction between the sample plate S and the measurement tube 4 is good, the radical binding heat Q5 can be accurately calculated, and therefore the recombination coefficient γ is accurately obtained. It is possible.

  The present invention is not limited only to the above-described embodiment, and can be changed within a range not departing from the gist of the present invention.

  In the above embodiment, the measurement tube 4 is a circular tube, but is not limited thereto, and may be a tube having an elliptical cross section. In this case, the support member 16 is also formed in a shape corresponding to the shape of the measurement tube 4.

  In the above embodiment, the sample tube is a square tube formed by a combination of four sample plates S, but is not limited thereto. For example, a tube having a pentagonal cross-sectional shape formed by combining five sample plates S may be used.

  Examples of the present invention and comparative examples will be described. In Examples and Comparative Examples, the radical measuring apparatus shown in the above embodiment was used except for the measuring tube, and the measuring tube had the following various configurations.

Example 1
A circular tube (φ84 mm × 350 mm) was used as a measuring tube. The support member shown in the above embodiment was disposed therein. As sample plates, four A5052 (aluminum: JIS standard) rolled plates (59.4 mm × 345 mm × 2 tmm: two, 55.4 mm × 345 mm × 2 tmm: two) were used. Four sample plates were arranged in a square tube shape on the support member. The measurement tube was provided with a shielding lid made of quartz.

(Comparative Example 1)
A φ84 mm × 350 mm circular tube made of sample material A5052 was used as a measurement tube. That is, the measuring tube itself was used as a sample tube.

(Comparative Example 2)
A square tube (outer diameter 60 mm × 350 mm, thickness 3 mm) was used as a measuring tube. Among them, two L-shaped plates (L54 mm × 345 mm × 2 tmm) which are plates made of A5052 and bent into an L shape as sample plates were combined and arranged in a tubular shape. The measurement tube was provided with a shielding lid made of quartz.

(Comparative Example 3)
A square tube (outer diameter 60 mm × 350 mm, thickness 3 mm) was used as a measuring tube. Among them, it is a plate made of A5052, and 4 A5052 rolled plates (54 mm × 345 mm × 2 tmm: 2 sheets, 50 mm × 345 mm × 2 tmm: 2 sheets) were used as sample plates. Four sample plates were arranged in a square tube shape on the support member. The measurement tube was provided with a shielding lid made of quartz.

  The ease of sample tube preparation was evaluated. The sample tube of Example 1 can be formed into a square tubular sample tube by combining four sample plates on a flat plate. On the other hand, the sample tube of Comparative Example 1 needs to process the sample material into a tubular shape. If the sample material is a material that can be welded, it is necessary to bend the flat sample material into a tube and weld it, and then weld the flange. If it is a material that cannot be welded, it must be made by cutting. For this reason, the cost is higher than in the case of the first embodiment.

In Comparative Example 2 and Comparative Example 3, although it is not necessary to process the sample material into a tubular shape, a gap was generated between the sample plate and the measuring tube due to the presence of R at the corner of the rectangular tubular measuring tube. That is, the adhesion between the measurement tube and the sample plate is lower than in the case of Example 1. Further, when welding the flange of the square tube, the gap became larger compared to the case of creating by cutting due to the occurrence of a welding beat.

  The case where the sample material was prepared by surface treatment was evaluated. When the sample material is expensive, the sample material may be obtained by subjecting a specific material to surface treatment. In the case of Example 1, it is only necessary to apply a surface treatment to a flat plate material, which can be facilitated. On the other hand, in the case of Comparative Example 1 and Comparative Example 2, since the material to be subjected to the surface treatment is not flat, the wet treatment such as anodizing treatment such as alumite treatment or chemical conversion treatment is still possible, such as vapor deposition or thermal spraying. Surface treatment is difficult.

  The thermal conductivity of the sample tube was evaluated. Measurement was actually performed in each radical measurement device having the measurement tubes of the above-described Examples and Comparative Examples, and the temperature of the temperature sensor and the outer wall of the measurement tube was measured. The measurement results are shown in FIG. In this measurement, the source gas was oxygen, a microwave power of 700 W, a gas flow rate of 1.5 m / s, and a temperature sensor position of 100 mm. As shown in FIG. 12, the temperature of the temperature sensor of Comparative Example 1 is about 70 ° C. lower and the outer wall temperature is about 2 ° C. higher than Example 1. The high outer wall temperature can be attributed to the difference in heat capacity in addition to the heat of recombination of oxygen radicals.

  In Comparative Example 2 and Comparative Example 3, the temperature of the temperature sensor was about 200 ° C. lower than that in Example 1. It is considered that the gap between the measuring tube of the square tube and the sample plate and the gap between the sample plates are affected. The higher the temperature of the temperature sensor, the better the S / N ratio can be measured, but it can be said that Comparative Example 2 and Comparative Example 3 are not suitable for accurate measurement. In Comparative Example 2 and Comparative Example 3, the outer wall temperature was also about 3 ° C. lower than in Example 1. This is thought to be due to the difficulty in transferring heat due to the gap between the measurement tube and the sample plate. As described above, it is considered that the configuration of Example 1 is easier to create a sample tube than the configurations of Comparative Examples 1 to 3, and more accurate measurement is possible.

2 ... Radical generation chamber 4 ... Measuring tube 9 ... Temperature sensor 10 ... Vacuum exhaust pipe 16 ... Support member 18 ... Shielding member

Claims (6)

A radical generation chamber having radical generation means for generating radicals of the source gas by generating plasma of the source gas;
A measuring tube communicating with the radical generation chamber;
Each of the sample plates is supported so that a tubular sample tube is formed by a plurality of sample plates made of a plate-like sample material for evaluating the rate of radical deactivation. A support;
An evacuation unit for evacuating the measurement tube;
A temperature measurement device comprising: a temperature sensor inserted through the sample tube and movable along the axial direction of the sample tube. The radical measurement device according to claim 1,
The support is in radical contact with the measuring tube and the plurality of sample plates. The radical measurement device according to claim 2,
A radical measuring apparatus further comprising a covering member disposed in the measuring tube and covering the support and the end surface of the sample plate so as not to be exposed in the measuring tube. The radical measurement device according to claim 3, wherein
The said support body consists of a support member which has a some 1st surface which contacts a surface of the said measurement tube, and a 2nd surface which contacts a surface of the said sample plate. The radical measurement device according to claim 4,
The measuring tube is a circular tube,
The said support body is a radical measuring device which supports the said sample board so that the said sample tube may become a rectangular tube. A measuring tube that forms a flow path for radicals;
Each of the sample plates is supported so that a tubular sample tube is formed by a plurality of sample plates made of a plate-like sample material for evaluating the rate of radical deactivation. A radical measuring tube comprising a support.

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